electric cars

NASA Eyes Electric Car Tech for Future Moon Rovers

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Space agencies are partnering with car manufacturers to custom build new rovers—or retrofit commercial vehicles—for future missions to the moon and Mars

NASA Eyes Electric Car Tech for Future Moon Rovers
Artist’s impression of a crewed NASA lunar rover (foreground), as well as the space agency’s robotic VIPER rover (middle ground) and a notional lunar lander spacecraft (background). Credit: NASA

Of the many “firsts” from NASA’s Apollo program of lunar exploration, one often overlooked is that the Apollo missions included the first—and so far only—times that humans have driven on another world. Presaging today’s eco-conscious market for carbon-neutral transportation, Apollo’s battery-powered lunar roving vehicles were all-electric as well. Astronaut David Scott, who was the first person to drive one on the moon during the Apollo 15 mission, remarked that the “moon buggy” vehicles were “about as optimum as you can build.” Astronauts used them in Apollo 16 and 17, too. During those missions, the vehicles traversed an average of just over 30 total kilometers of lunar terrain and reached a top speed of 18 kilometers per hour. These vehicles were considered disposable: each ran only for a matter of hours before being discarded on the moon at mission’s end.

Fast-forward to today, when NASA is once again aiming for astronauts on the moon: the space agency’s Artemis III mission is slated to ferry a crew to the vicinity of the lunar south pole as soon as 2025. But this time an Apollo-like moon buggy will not suffice. NASA’s plans call for Artemis’s first moonwalking astronauts to spend a week exploring the region around their landing site, which is intended to become a sort of base camp for future lunar forays. For those sorts of high-endurance operations, a suitably high-endurance vehicle would be desirable, too. Last August NASA said as much in a video announcing a request for information for a new lunar terrain vehicle. “This isn’t your grandfather’s moonbuggy,” read bold text in black and pink while an electric guitar vamped in the video, “but it might be his granddaughter’s”—an allusion to Artemis III’s goal of putting the first woman on the moon.

Importantly, the lunar terrain vehicle is just one member of the automotive fleet that will support Artemis’s astronauts. The Volatiles Investigating Polar Exploration Rover, (VIPER), another lunar rover, will not chauffeur people but instead will roam uncrewed around the moon’s south pole for 100 days in search of water ice. The agency is also considering a third vehicle—a pressurized “habitable mobility platform” that could transport crews for up to 45 days.

The crewed lunar terrain vehicle should be designed to last at least a decade, according to NASA’s requirements. It would support a bevy of one- and two-week missions, and it could even explore the surface of the moon autonomously between human visitations. Moreover, its design would set the standard for subsequent generations of surface vehicles built to support notional future human landings on Mars.

In response to those challenges, space agencies are drawing on the deep experience of commercial automobile manufacturers to design durable rovers from scratch. At least two partnerships have sprung up to vie for NASA’s next lunar terrain vehicle: One between General Motors and Lockheed Martin was announced last May. And another between Northrop Grumman, AVL, Intuitive Machines, Lunar Outpost and Michelin launched last November. Planetary scientists have even started to think beyond the moon: a recent Keck Institute for Space Studies workshop convened agency, academic and industry researchers to consider bolder ideas for the Martian surface, such as retrofitting a commercial electric vehicle for space use.

Across the Pacific, Japan is undertaking a parallel process. The Japan Aerospace Exploration Agency (JAXA) has partnered with Nissan and Toyota for two different lunar driving projects. In December Nissan unveiled an uncrewed lunar rover prototype that incorporates front and rear electric motors to navigate bumpy terrain. Toyota, meanwhile, is designing a crewed, pressurized lunar cruiser that is powered by hydrogen fuel cells and would ostensibly fill the same role as NASA’s habitable mobility platform. Toyota officials announced in January that, following the cruiser’s deployment to the moon, the company will work on adapting it for use on Mars.

“We’re converging on a point for planetary and commercial vehicles where we’re utilizing the same kinds of techniques to operate these vehicles, get them to drive autonomously and avoid obstacles,” says Paul Niles, a planetary scientist at NASA’s Johnson Space Center. “Certainly, automation would help, and that kind of [partnership] would be really synergistic.”ADVERTISEMENT

“EXTRATERRESTRIAL” MEANS “EXTRA DIFFICULT”

The moon and Mars present an overlapping set of difficulties for a reusable rover. The first step is simply getting there: although SpaceX hopes to greatly lower the cost of launches with Starship, the company’s in-development and purportedly fully reusable heavy-lift rocket, putting anything as big as a car into space remains a lofty investment. (Then again, SpaceX has already done that, too—and has whimsically teased what could be nascent plans to someday send a Tesla Cybertruck to Mars.)

Once deposited on either body, a vehicle would have to contend with unearthly extremes in temperature. Mars receives only about half as much of the sun’s warming radiance as Earth, and the Red Planet’s atmosphere is too tenuous to hold on to much heat, Niles says.

“On your worst day on top of Mount Everest, it’s like your warmest day on Mars,” he says. “While the rocks on the surface can actually get pretty warm, almost up to zero degree Celsius, the air is really cold.”

The situation on the moon is even more extreme. The moon rotates more slowly than Earth, making a lunar day last around 29.5 Earth days. This means a multiuse vehicle would have to survive a weeks-long lunar night—a feat that derailed China’s Yutu rover in 2014. Temperatures can reach a blistering 127 degrees C during lunar days, only to plunge to –173 degrees C during lunar nights. Furthermore, the moon’s lack of a heat-distributing atmosphere means that shadowed regions can become extremely cold, even during the long lunar day. For a rover to endure these extremes, it must somehow store energy and retain heat through the lunar night without access to solar power—but it must also avoid overheating when bathed in harsh sunlight for weeks at a time.

“Being able to survive that [lunar] night is absolutely critical, or you’re just throwing up disposable rovers at that point,” says Derek Hodgins, strategy and business lead of Lockheed Martin’s lunar exploration arm.ADVERTISEMENT

Another hurdle that a vehicle must surmount in space is radiation. Earth’s atmosphere and magnetic field act as shields against high-energy particles ejected by the sun and cosmic rays, each of which can degrade materials and damage delicate electronics. But neither the moon nor Mars offers similar protections. Surface rovers meant to operate there for years on end must include radiation-hardened electronics, as well as greater redundancies in the inevitable event of parts-based failures, says Jeff Nield, director of product and experience for global industrial design at General Motors.

Finally, the moon and Mars possess a much weaker gravitational field than Earth, which can subtly affect a vehicle’s operations. Less gravity may actually help an electric-powered vehicle carry burdens such as astronauts and travel farther than a similar car on Earth could with the same power supply. But the calibration and suspension of a rover on the moon or Mars would need to be adjusted for an altered center of gravity, says Bethany Ehlmann, a planetary scientist at the California Institute of Technology.

SOLUTIONS: FROM SCRATCH OR OUT OF A BOX?

The two partnerships designing lunar vehicles for NASA are undeterred by these challenges, enough so to develop their prototypes without the certainty of a contract with the agency. NASA has solicited multiple requests for information for the lunar terrain vehicle, but it has yet to release a formal request for proposal, which would signal its ability to foot the bill.

“There’s never been an 100 percent industry-led development of a human space system that has flown or held American astronauts,” Nield says, adding that the recently completed Commercial Crew Program received 7 percent of its funding from industry, with NASA picking up the remaining 93 percent of the multibillion-dollar tab.

GM and Lockheed Martin’s bet is probably not all that risky, though: According to Hodgins, the Apollo missions generated up to a 700 percent return on investment for industry partners, based on technology that was developed for space and applied to Earth. These included pumps for artificial hearts and some of the flame-resistant materials used in firefighting suits.ADVERTISEMENT

This time around, the translatable innovations may be related to autonomous driving and user ergonomics. Autonomous technology would allow a rover to scout potential landing sites, pre-position cargo and collect samples to prepare for or augment crewed missions. And designing a vehicle’s cabin to better accommodate spacesuit-clad passengers and crew would be essential. Improvements in both areas could cascade into consumer products on Earth in the form of better self-driving cars or vehicles with enhancements for users with limited mobility. The GM–Lockheed Martin rover, for instance, has a roomier, more astronaut-amenable interior where grab handles aid movement and glove-friendly buttons and switches take priority over touch pads.

But this sort of custom-built approach is only one solution to the space problem. Other researchers, Niles and Ehlmann among them, see potential for designs that simply use an existing consumer electric vehicle’s chassis and then retrofit it with adaptations needed for extraterrestrial operations. They both contributed to the workshop last March on revolutionizing access to Mars’s surface that was borne out in a Keck Institute for Space Studies report published this month. The report’s appendix concluded with a case study on the cost and process of adapting an off-the-shelf commercial electric vehicle for Mars.

In theory, if enough components remain untouched, the cost of revamping an existing vehicle would be much lower than designing one from scratch, says Ehlmann, who co-led the workshop.

Commercial electric cars have more features that would suit them for Mars in addition to their batteries and ability to function at low temperatures. Despite differences in atmospheric pressure on Earth and Mars, sealed and pressurized components of the cars would likely not be affected, according to the report. Additionally, commercial vehicles have gone through years of stress testing to be sold on the market, in contrast with rovers tailor-made for space.

Still, Ehlmann says the idea remains only a thought experiment. The report’s off-the-shelf approach, however, represents the sort of outside-the-box thinking that could hasten progress toward human voyages to Mars.ADVERTISEMENT

“There’s so much excitement about the science to be done,” she says. “It’s useful to think about missions not as one-offs but as a real commitment to have a U.S. presence on the moon and Mars, both robotically and one day in person.”

Are electric cars greener? Depends on where you live

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Long thought a thing of the future, electric cars are becoming mainstream. Sales in the United States of plug-in, electric vehicles nearly doubled last year. Credible forecasts see the number rising within a decade to half a million vehicles per year, which would easily exceed sales of the Toyota Camry today.

Although the technology for electric cars is improving quickly, the industry still depends heavily on public policy – such as the $7,500 subsidy that the federal government gives everyone who buys one. The rationale for such aggressive policy support is, in part, rooted in the idea that these cars cause less pollution. Indeed, conspicuously “green” consumers dominate sales of electric vehicles, just as they did initially for hybrid vehicles such as the Toyota Prius.

But whether electric cars are actually greener depends on where the comes from. Our research, along with other studies, finds that electric cars are not necessarily the environmentally friendly choice when it comes to the of – the pollutant of greatest concern for .

It is true that electric cars have no tailpipe emissions (they don’t even have tailpipes!), which means they can help clear local air. But the electricity used to charge these vehicles comes mainly from power plants that burn coal or natural gas, with coal being the biggest emitter. Other sources of electricity – wind, solar, hydro and nuclear – generate zero emissions.

Figuring out whether the electricity is more environmentally friendly than just burning gasoline directly in cars depends on statistical sleuthing to estimate changes in emissions within the overall electricity grid in response to the additional electricity needed to charge an electric car. We’ve done this using data on every hour of every day for recent years across the nation, and the results are striking.

Where and when electric cars are charging affects how their emissions compare with the alternatives of a conventional or hybrid car. In some places and at some times, electric cars generate more emissions. We find, for example, that charging an electric car at night in the upper Midwest will generate more carbon dioxide per mile driven than the average conventional car that burns gasoline. In contrast, electric cars in the western United States and Texas always generate lower emissions than even a hybrid, and this arises because rather than coal tends to be used for generating the additional electricity in these regions.

Our findings are based on how electricity is actually generated and current technologies that determine the efficiency of vehicles. But how might things change in the future to affect whether electric cars will reduce emissions and therefore help address climate change? We know the fuel economy of non-electric cars will increase in the coming years. The U.S. Environmental Protection Agency has nearly doubled the average fuel efficiency goal for cars by 2025. Meanwhile, the manufacturers of electric cars are seeking to significantly increase the distance that one can drive on a charge.

But the critical driver of electric-car emissions is how the electricity is generated. And this is where the future of electric cars as a means for addressing climate change is related to the future of power plant regulations. The EPA is in the process of developing its “Clean-Power Plan” to reduce emissions from . This, along with other rules, will make the electricity sector cleaner and help ensure that electric vehicles are the green choice down the road.

More than 100 years ago were the dominant and most promising technology for powering personal automobiles. But oil won that battle and reigned over the 20th century. Now electricity is poised to make a comeback, and might yet power the transportation sector this century. The push is due in large part to concerns about climate change, so it is important to have policies that ensure are part of the solution rather than the problem.

Secretive Company Claims Battery Breakthrough.

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Two of the most sacred numbers in the electric-vehicle industry are 300 miles and$100. The first is generally considered to be the distance electric cars need to travel on a single charge for Americans to take them seriously. The second is the cost, per kilowatt-hour, to which batteries need to drop before EVs can compete with gas-powered cars on sticker price.

Sakti3 battery

Sakti3, a Michigan startup that auto-industry insiders have been whispering about for years, says it might soon hit those two sacred targets. The company has long been in semi-stealth mode, talking to the press but offering few particulars about its technology. Now, Ann Marie Sastry, co-founder and CEO of the company, tells me that the company’s prototype solid-state lithium battery cells have reached a record energy density of 1,143 Watt-hours per liter— more than double the energy density of today’s best lithium-ion batteries.

Sakti3’s technology is solid-state battery produced with the same thin-film deposition process used to make flat panel displays and photovoltaic solar cells. The cell contains no liquid electrolyte; an “interlayer” acts as both the separator, which keeps the positive and negative electrodes from coming into contact, and the electrolyte, allowing desirable ion transfers to take place. Sastry says Sakti3 will commercialize its technology in a couple of years, and the first application will be consumer electronics. If all goes according to plan, electric-vehicle batteries will follow. And if Sakti3 delivers what it says it has, it could be the kind of battery to give us the 300-mile, $25,000 electric car.

Before everyone starts talking about the imminent arrival of the God Battery, however, some important caveats. Most of the technical details remain secret. The energy-density claims have yet to be independently verified. Turning a tiny prototype cell into a road-worthy car battery is a huge and uncertain undertaking. And the battery industry has a proud, century-long tradition of overpromising and underdelivering.

For what it’s worth, Sastry seems to understand all of this. “We’ve had several cells and runs that have demonstrated these numbers to the point that we’re confident,” Sastry says.

For all its secrecy, Sakti3 is not an unknown quantity. If, in the past six or seven years, you’ve interacted with anyone at General Motors involved with the Chevy Volt, you’ve heard about Sastry and Sakti3. The story has always been this: Sakti3 is working on this new solid-state technology that could leapfrog lithium-ion—but that’s all I can tell you.

By now the company has received millions in funding from backers including Khosla Ventures and GM Ventures, the automaker’s tech-investment arm. Jon Lauckner, the former General Motors executive who was the brains behind the Chevy Volt, and who now leads GM Ventures, sits on Sakti3’s board.

The company grew out of the engineering department of the University of Michigan. Sometime in 2006, Sastry and her colleagues began doing complex mathematical optimization schemes trying to figure out which of the many competing variables that go into an electric car battery—energy, power, mass, volume, cost, safety—could give. Their calculations told them to get rid of the liquid electrolyte found in conventional lithium-ion batteries, along with all of the extra packaging that a liquid electrolyte entails.

It’s easy to see why. The electrolyte in a lithium-ion battery is a liquid not unlike gasoline, and it’s responsible for many of the secondary chemical reactions that over time degrade batteries or, worse, cause meltdowns and fires. Because of the delicacy of the liquid electrolyte, lithium-ion battery packs used in cars are often shrouded in packaging—liquid cooling tubes, electronic controls, and so on. Those things add cost and weight.

But it’s not easy to get rid of the electrolyte. People have tried. Notable failures include the Canadian company Avestor, which filed for bankruptcy in 2006 after the solid-state lithium batteries it sold AT&T began detonating inside U-Verse cable boxes around North America.

Avestor used a polymer separator to replace the electrolyte in its batteries. We don’t know what Sakti3 is using—that’s a trade secret. The composition of the positive electrode also remains a secret; Sastry says it is nothing unusual—“a very well understood electrochemistry.” We do know that, like most of the promising post-lithium-ion battery chemistries identified so far, the Sakti3 battery has a metallic-lithium anode, or negative electrode.

The vacuum deposition process Sakti3 uses to manufacture its cells is significantly different from the lamination process most battery makers use. Lithium-ion battery factories look like a combination between a printing press and an industrial bakery. In huge industrial mixers, chemical powders are blended into a wet slurry; that gets coated onto sheets of metallic film, which is then chopped into electrodes, which are placed in pouches with the electrolyte and other components.

In the solid-state manufacturing process, by contrast, the layers of the thin-film battery are deposited sequentially—first the cathode, then the current collector, then the interlayer, anode, and so on. The entire process takes place in a vacuum chamber.

It’s not immediately apparent how working in a vacuum chamber could ever be cheap, but Sastry says there are cost benefits. “First, solid-state does not have any aging requirement. Cells come out fully charged and ready to test, where with the incumbent technology cells need 30 to 60 days” before you can use them. “Next, it’s very high throughput.” The manufacturing rate, she says, crippled earlier solid-state-battery efforts. “When we started there were a number of solid-state batteries in the literature,” she says. “They were made exclusively on platforms that would always be expensive due to the rate. Our numerical simulations told us to restrict our efforts to cheap tooling,” like the custom prototype line the company is using today.

Sakti3 also benefits from the passage of time. They get to take advantage of the huge amount of engineering that has gone into manufacturing processes for solar panels, flat-panel displays, and other solid-state electronics. “While we were working on our technology there were significant advances in cost in technologies that are very similar to ours,” Sastry says. “We will benefit from those.”

All of this, she says, is why Sakti3 should eventually be able to hit that goal of $100 per kilowatt-hour.

There are plenty of other variables to consider. What about cycle life—that is, the number of times the battery can be charged and discharged before it starts to become worthless? Sastry says that because the chemical reactions in her cells are much simpler than those in conventional lithium-ion batteries, they should last longer. “We expect great cycle life.” What about safety? “Solid state eliminates the riskiest part of the battery cell,” she says. “You can snap one of the batteries into two pieces. Drop hot solder on it and it continues to operate.”

One of the few experts privy to the details of Sakti3’s work is Wei Lu, a professor of engineering at the University of Michigan. Lu says he has no direct involvement with Sakti3 and no financial ties to the company. He also says he is impressed. “They have a very rigorous testing facility,” he says. “Their results are highly impressive and very accurate.”